Jsm 5900

The variation of Mg alloy by corrosion can be analyzed by measuring the mass loss in a solution where the media volume-to-surface area ratio is at least 50 mL/cm² of HBSS^{44 (link)}. Thus, each specimen was immersed in 500 mL of HBSS and kept in an incubator with 5% CO₂ at 37 °C for 1 week and 2 weeks, respectively. After the immersion test, the specimens were removed from HBSS and dried at room temperature. The corrosion morphology and components of the surface were characterized by scanning electron microscopy (SEM; JSM-5900, JEOL, Japan), and energy dispersive spectroscopy (EDS; 7274, Oxford Instruments, England).
To measure the mass loss, the corrosion products on the surface were removed by soaking in chromic acid solution. The acid solution was manufactured by mixing 200 g/L of chromic acid, 10 g/L of silver nitrate (AgNO₃), and 20 g/L of barium nitrate [Ba(NO₃)₂] according to American Society for Testing and Materials (ASTM) G1⁴⁵ . The average and standard deviation of three measurements was calculated for each group. The corrosion rate was calculated using the following equation according to ASTM G31–72⁴⁶ : $$\mathrm{C}=\left(\mathrm{KW}\right)/\left(\mathrm{ATD}\right)$$ where C is the corrosion rate (mm year⁻¹, mmpy), the constant K is 8.76 × 10⁴, W is the mass loss (g), A is the specimen area exposed to solution (cm²), T is the time of exposure (h), and D is the density of the material (g/cm³).

For SEM analysis, the 46-h-old biofilms were washed three times with 0.1 M cacodylate buffer and fixed with a 3% glutaraldehyde solution for 1 h, followed by post-fixation with a 1% osmium tetroxide solution for 1 h^{24 (link)}. The biofilms were dehydrated using a graded ethanol series (30–100%) and penetrated with nitrogen gas. Finally, the biofilm samples were sputter-coated with gold–palladium and observed by SEM (JSM-5900, Jeol, Japan).

Hydrogels were characterized by FTIR-ATR spectroscopy in a Nicolet iS5 Thermo scientific (USA) with 16 scans from 4000 to 650 cm⁻¹. The size of synthesized AgNPs was determined by dynamic light scattering using Malvern Zetasizer Nano S, and their shape was determined by scanning electron microscopy (SEM, JEOL JSM-5900, Tokyo, Japan) operating at 200 kV. Solid-state crosspolarization magic angle spinning carbon-13 nuclear magnetic resonance (CP/MAS ¹³C-NMR) was used to analyze the structure of grafted films in a Bruker Avance III HD at 400 MHz. Tensile test specimens of hydrogels were adequately cut for analysis of mechanical properties of samples according to ASTM standards. For this analysis, were used hydrogels freshly prepared; samples were evaluated in an AGS-X-Shimadzu extensometer under the following conditions: 44% moisture, an extensional speed of 10 mm/min at room temperature. The measurements were carried out by triplicate for each sample, and data of a specific sample were plotted.

The chemical composition of mussel seashells powder was determined by X-ray fluorescence spectrometry (XRF, ARL ADVANT’XP). In addition, the particle size distribution of the mussel shell powder was measured by using a laser particle size analyzer (Malvern, Mastersizer 2000). Rigaku D/Max-2500 XRD, Cu-Kα (1.541874 Å) was used to investigate the phase structure of the prepared samples.
The physical properties of CCNPs were tested by the following characterization: particle morphology disclosed through a scanning electron microscope (SEM, JEOL JSM-5900); and the thickness of CCNPs were considered by atomic force microscope (AFM, Veeco Autoprobe CP Research).

Afte exposing to DMAB(P)-Ch, the fungal hyphae were briefly washed in sterile water. Primary fixation of fungal hyphae was done with 2.5% glutaraldehyde and 2% paraformaldehyde buffered with 0.01 M phosphate buffered saline for 4 h at 4°C. Post fixation was done with 1% osmium tetroxide (Tedpella, Redding, CA) in 0.05 M PBS pH-7.2 for 2 h. Samples briefly washed with distilled water at room temperature and kept at 4°C with 0.5% uranyl acetate (EMS, Hatfield, USA). Samples were dehydrated with graded ethanol series 30, 40, 50, 60, 70, 80, 90% and three changes of 100% ethanol 10 min for each alcohol dilution. The samples were kept in a vacuum desiccator until they were completely dry. Samples were placed on a stub coated with carbon electron conductive tape. Sputter coated with platinum for 120 s and examined under scanning electron microscope (JEOL JSM-5900, Japan).

Pitaya epicarp for each coating and control were cut into 4 mm × 10 mm samples and immersed in 5% (v/v) glutaraldehyde for 24 h. Then, samples were fixed with OsO₄ 1% (w/v) for 2 h, dehydrated in a graded alcohol series, and covered with carbon and gold before examination in a JEOL JSM-5900 (LV, Tokyo, Japan) microscope [41 (link)]. Fresh fruit was inoculated with spore suspension of 1 × 10⁴ spores·mL⁻¹ of Alternaria sp. (Culture Collection of Centro de Biotecnología Genómica of Instituto Politécnico Nacional, Reynosa Tamaulipas, Mexico) by a puncture and stored at 10 °C and 80% of RH for 9 days. Samples were taken and prepared for SEM analysis as described above.